RESUMO
PURPOSE: Nasal Cellulose Powder (NCP), which can prevent from binding an allergen to nasal mucosa, may reduce allergic rhinitis (AR) symptoms in dust mite-sensitized children. This study was conducted to assess the efficacy of NCP in improving clinical symptoms of a nasal airflow limitation and the response of nasal inflammatory cells. METHODS: Children with dust mite-sensitized AR aged 6–18 years were recruited. After a 4-week run-in period, NCP or a placebo was administered, 1 puff per nostril 3 times daily for 4 weeks. The nasal provocation test (NPT) with Dermatophagoides pteronyssinus (Der p) was performed before and after treatment. The daily symptom scores (DSS), daily medication scores (DMS), the peak nasal inspiratory flows (PNIF), nasal airway resistance (NAR), as well as the maximum tolerated dose of NPT and eosinophil counts in nasal scraping, were evaluated. RESULTS: Sixty children (30 NCP and 30 placebos) were enrolled. Before treatment, there were no significant differences in age, dust mite control measures, DSS, DMS, PNIF, NAR, the maximum tolerated dose of NPT, or nasal eosinophil scores between children receiving NCP and placebos. After treatment, there were no significant differences between the NCP and placebo groups in the median (range) of the outcomes—DSS: 2.06 (0.18–3.77) vs. 1.79 (0.08–7.79), P=0.756; DMS: 1.60 (0–5.13) vs. 0.56 (0–4.84), P=0.239; PNIF (L/min): 110 (60–160) vs. 100 (50–180), P=0.870; NAR (Pa/cm³/s): 0.40 (0.20–0.97) vs. 0.39 (0.24–1.32), P=0.690; the maximum tolerated dose of NPT and the nasal eosinophil scores: 1 (0–4) vs. 1 (0–4), P=0.861. CONCLUSIONS: NCP treatment may not be more effective than placebo treatment in dust mite-sensitized AR children.